Spring annealing machine



July 27, 1954 1 P. DRUEHL SPRING ANNEALING MACHINE 5 Sheets-Sheet l Filed Oct. 6, 1950 INVENTOR.

July 27, 1954 L P. DRUEHL SPRING ANNEALING MACHINE 5 Sheets-Sheet 2 Filed Oct. 6, 1950 lrlllll July 27, 1954 P. DRUEHL 2,685,019

SPRING ANNEALING MACHINE Filed Oct. 6, 1950 5 Sheets-Sheet 3 INVENTOR.

July 27, 1954 L. P. DRUEHL SPRING ANNEALING MACHINE 5 Sheets-Sheet 4 Filed OCL. 6, 1950 I NI "EN TOR. Zoe/3 au/fae/Z July 27, 1954 L. P. DRUEHL SPRING ANNEALING MACHINE 5 Sheets-Sheet 5 Filed OCC. 6, 1950 [NVE TOR. el

Patented July 27, 1954 UNITED STATES PATENT OFFICE SPRING ANNEALING MACHINE Louis Paul Druehl, Oak Park, Ill. Application October 6, 1950, Serial No. 188,846

(Cl. 21S- 11) 30 Claims.

This invention relates to a spring annealing machine which is more specifically adapted to provide a structure for annealing individual springs. rThis machine is used for annealing springs of the type more commonly found in upholstery, mattresses or bedsprings. The machine is also capable of accommodating wire or springs which can be of variable coil diameter within certain limits within the operative functions of this machine.

Various practices have been followed in the past in annealing springs and analogous products of this type such as batch annealing, which has not been found entirely satisfactory to produce a uniform spring of a given tension and resiliency. It has also been the practice to resort to excessive handlingr of the springs of this nature to carry out the annealing process.

It is one of the main objects of the present invention to provide a means which can be employed for quickly and eliciently annealing individual springs as they are fed into and extracted from the machine of this invention.

It is another object of this invention to produce a machine of this character which can be employed in the form of an attachment to wire or rod forming machines for the purpose of ree ceiving the individual spring coils in timed relation from the forming machine to individually anneal each spring at a given cyclic arrangement with respect to the forming machine. In this respect, the annealing machine has been designed to receive the springs directly from the forming machine by placing the attachment in line with the conveying -chanisms that deliver the ier-med springs from the forming machine to a point of discharge. This point of discharge in this case will be the annealing station or" the machine of the present invention at which point the spring is actuated by the discharge mechanism of the forming machine. In other Words, this annealing machine as an attachment can be placed in the spring production line in the position wherein the spring is usually discharged through a trough or from other controlled delivery mechanisms as is the usual practice with forming machines.

It is another object of this invention to substantially take the spring as formed and to convey it into a given space which will determine the nnal overall length of the spring and to anneal the spring when disposed between the gauge means provided.

It is another object of this invention to provide an annealing machine which is electrically conlil 2 trolled to position the spring before the annealing cycle begins and to interrupt the annealing cycle before removing the spring from its electrical energy source that is provided to heat the spring during the annealing cycle.

It is still a further object to control the heatn ing interval of the spring at the annealing station.

Other objects and advantages relating to the annealing machine of the present invention shall hereinafter appear in the following detailed description having reference to the drawings which form a part of this speciiication.

In the drawings:

Fig. 1 is an end elevational view of the annealing machine with certain parts broken away and in section to better illustrate the same Fig. 2 is a diagrammatic View to illustrate one manner of feeding individual springs from a supply to the annealing station of the machine;

Fig. 3 is another end elevational view of a modied construction of annealing machine embodying certain other principles of operation;

Fig. 4 is an end elevational view of another modied construction utilizing the principles set forth by this invention;

Fig. 5 is a vertical cross sectional view taken substantially along the line 5 5 in Fig. 4 to show certain other details of construction of the Fig. 4 modification;

Fig. 6 is a general circuit diagram illustrating the main principles oi electronic control herein utilized in operating the machine of the present invention;

Fig. '7 is a fragmentary view of an outside portion of one oi the panels illustrating a removable electrode construction;

Fig. 8 is a vertical sectional view taken along the line 3 3 in Fig. 7 to illustrate further details of construction of the removable electrode unit;

Fig. 9 is a diagrammatic view illustrating the relationship between one end of the spring and its adjacent electrode;

Fig. 10 is a similar View showing the relationship of the other end of the spring and its adiacent electrode;

Fig. 1l is a diagrammatic view of a spring oetween the panels of the machine to illustrate certain beneits obtained by annealing springs with the machine cf the present invention; and

Fig. 12 is a diagrammatic perspective of another type of spring to illustrate certain other benefits obtained through the use of the present machine in annealing springs.

Referring to Fig. l, the annealing machine of the present invention comprises in general a pair of longitudinally arranged insulating panels i and 2 spaced apart laterally by one or more brackets 3 to provide a given distance between the panels with the latter providing guide means for the reception of a spring 5. Springs such as l may be successively fed into the position indicated by operable feed fingers 5 and 53 so as to be gripped and held in this position by means of a solenoid mechanism 1 that is arranged to hold and force the spring ends 8 and E against a pair of electrodes i@ and il. As the springs i are brought into the station or position indicated in Fig. l, the end coils ci the springs rest upon positioning bars i2 and i3 that are laterally arranged between said guide means and represent continuations of guide rails lil, one ci which is indicated in Fig. 2.

As best shown in Fig. 2, the individual springs i may be ied down the guide rails ld by gravity into a suitable position that may be determined by a pair of buttons l5 for engaging either end of the springs d and which may be mounted upon the side guide panels it. The iingers 5 and ii are illustrated as a portion ci an advancing mechanism housed within the chamber i1 which will act to advance the fingers 5 and horizontally between the solid and dotted line positions shown in Fig. 2, and which will retract and return the nngers to engage behind another spring. Each time one of the springs is advanced to the annealing station indicated at iS, the previously annealed spring will be pushed oil the end of the bars l2 and i3 to be collected in a suitable container or stacker.

Referring again to llig. l, the solenoid operating mechanism 1 is mounted centrally between the panels l and 2 upon a bracket l secured at 2*! to one of the panels. IThe solenoid 2i is provided with flange means 22 adapted for bolting to the horizontal leg of the bracket iS which will rigidly hold the solenoid 2l as seen in Fig. 1. The solenoid 2i has a plunger t3 connected with a block 2li by means oi a bolt 25 passing through the block 2 and through aligned openings in the vertically operable spaced plates 2 and 21 of the plunger. A laminated core 23 is secured integrally with plates 25 and 21, and the entire plunger is guided within solenoid 2l and vertically within an opening 2s in bracket le as the plunger is driven upwardly by energization of the coil of solenoid 2i. A clevis 3| is positioned above the block 24 for sliding movement between the plates 2t and 21 and a pair of headed pins 32 are secured to the clevis and are vertically slidable in openings 33 formed in the block 2&5. Clevis Sil vincludes a central bore Se having a compression spring 35 therein which engages between the bottom of the bore 3d and the top of the block ifi to provide a resilient means interposed between the clevis and the block for providing a variable feature in the operation of the present device.

levis 3i carries a pivot pin 35 to which a pair oi toggle links 31 and 33 are pivotally attached, and the outer ends of the links 31 and 38 are connected by pins St and [il] to the rockable fingers il and t2. Fingers li and 42 are connected to nxed supports [i3 and @lil by means of pins i5 and e so that the spring gripping ends G1 and l of the fingers il and l2 can be brought into operative engagement with the spring ends il and 9 when the latter are in the annealing station position supported upon the bars l2 and i3. The terminal portions of the spring gripping ends 41 and i8 are inclined as at 139 and 5l) as indicated in Fig. 1 to provide a gripping surface on each of the gripping lingers that will tend to keep the spring ends down against the support bars I2 and i3, and also laterally outwardly with respect to the solenoid and against the electrodes lll and il.

The illustration in Fig. 1 of the machine of this invention shows the solenoid 2 I as energized from a current source through the wires 5i and 52 which has moved the plunger 23 upwardly carrying the upward thrust on block 24 through the spring 35 against the clevis 3l which will straighten the toggle between the links 31 and 38 to lock both of the gripping ngers All and i2 for holding the spring 1l against the electrodes Il! and l I in an annealing position. By suitable time delay or time control mechanism, the electrical circuit can produce a given current through the wires 53 and 54 which are attached by nuts 55 and 56 to the electrodes l0 and il to pass the current through the spring ii from one to the other of the electrodes, thus heating springs 4 to a given temperature and for a given length of time. The electrical circuit also includes means through the time control mechanism which will interrupt the current to one of the other of the electrodes, therefore shutting off the flow of current through the spring Il after a predetermined interval of time.

It is one of the objects of this invention to be able to bring a spring such as i into the position indicated in Fig. 1 before current passes between the electrodes lll and l l through the spring. Then by automatically operable means such as diagrammatically illustrated at 51 having switch contacts 53 operated by a plunger 59 that is actuated through a head 6D as the spring i stops in the annealing station, it is possible to set the electrical system in cyclic operation through a time interval to produce the sequence referred to in annealing a spring such as 4.

Thus Fig. 1 illustrates the use of a time annealing mechanism using a vertically operable solenoid structure which actuates a pair o gripping members simultaneously to hold the ends of a spring against panels in a given relation to each other, and wherein the ends of the spring are in contact with electrodes that will function to pass current through the spring for heat treating such a unit. With the use of the resilient connecting clevice and block 24, it is obvious that the spring wire thicknesses may be varied without affecting the operation of the mechanism, and the variations in the parts and the pivotal connections can all be readily compensated for by reason of the cushioning effect created between the clevice 3l and block 2Q. t is also obvious that various diameters of coil springs can likewise be fed through a channel between the panels l and 2 and that the gripping mechanism will still function in its designed capacity to grip the spring against the electrodes for the annealing cycle of the machine.

Referring now to the modied arrangement illustrated in Fig. 3, this construction also involves 4a pair of panels 6i and 62 that are adjustably connected by means of the bolts '53 and td to the vertical legs E5 and 66 of brackets 61 and 68. The latter are also adjustably connected by bolts such as 69 to a supporting bed 1!) common to the supported mechanism of the machine. This construction entails more speciiically the use of a pair of solenoids 1I and 12 having plungers 13 and 1li that carry rollers 15 and 16 which are arranged to operate the gripping lingers 11 and 13. Rollers 15 and 16 operate upon guide rails 19 and 80 which are bolted in place at 8| and 82 to the panels 6| and 82.

The gripping fingers 11 and 18 in this construction are pivotally supported upon the pins 83 and 84 on the spring supporting bars 85 and 85. These fingers terminate with gripping ends 81 and 88 which contact the spring ends 89 and 90 of a spring 9|, and are also provided with leaf springs 92 and 93 which coact with the rollers 15 and 1'8 of the plungers 13 and 14 to cause such fingers to oppositely rotate upon their pivots for the purpose of gripping the spring ends. By the use of the leaf springs 92 and 93 various thicknesses of spring wire may be gripped and a resilient connection introduced between the iingers and the plungers that will allow certain tolerances in construction which will help to produce a less expensive annealing machine. It should also be noted that the fingers 11 and 18 are provided with tails 94 and 95 which help to shield the leaf springs 92 and 93 from the heat of the spring being annealed, and which tails also provide weighted ends to normally maintain the gripping ngers in inoperative positions with the springs 92 and 93 in engagement with the rollers and 15, one of such positions being shown in dotted lines in the left hand portion of Fig. 3. This construction includes the electrodes 96 and 91 that are suitably supplied by electrical currents through the wires 98 and 99 to pass current through the spring 9| to heat the latter for annealing.

It is to be understood that the guide bars y85 and 86 are preferably made of metal although they may be constructed of an insulating material such as Bakelite as are the panels 6| and 82. This same construction prevails in the Fig. 1 device so that the guide bars l2 and |3 may be made of metal or of insulating material. When the bars are of insulation, they will isolate the electrodes in each of these constructions to obtain a predetermined current ilow only through the spring which is located in the annealing position should conditions or materials require such isolation.

In the Fig. 3 structure, the solenoids are horizontally mounted to permit the supporting of the mechanism upon the base 10 previously described, which base may be a portion of the wire forming machine. This latter construction also contemplates the use of individually operable gripping fingers which are simultaneously operated through simultaneous current introduction through the wires |00 and |01 into the solenoids 1| and 12. It is also possible with this construction to individually operate ngers 11 and 18 at slightly diierent intervals or at different levels should either or both of these relations be desirable.

Figs. l and 5 are directed to a construction which uses magnetic holding means in place of the solenoid operated gripping fingers described in the first two annealing machine constructions. Fig. 4 illustrates two panels |02 and |03 of insulating material such as Bakelite, receiving the spring I 04 therebetween upon the insulated guide bars `|05 and |06 at the annealing position opposite the electrodes |01 and |08. As seen in Fig. 5, each panel mounts a pair of magnets |09 and ||0 that are laterally spaced for the purpose of contacting any one of a number of springs within a given diameter range. In this construction a suitable plunger operated switch means can be utilized in the magnetic circuit to introduce a holding circuit that will energize' the magnets |09 and ||0 for holding the spring |04 in the position indicated. The circuit is arranged to introduce current through the electrodes |01 and |08, immediately after the holding circuit has been established, to heat the spring for the purpose of treating the same. Thereafter the electrodes are de-energized before the magnetic circuit breaks, thus eliminating or reducing electrical arcing to a negligible minimum. The construction or" the annealing machine contemplated in Figs. 4 and 5 has the facility of eliminating a good many mechanically operable mechanisms and may be well adapted for use under certain conditions of operation, particularly where space limitations are important.

Referring now to the circuit diagram illustrated in Fig. 6, this diagram is applicable to the constructions shown in Figs. 1Y to 5 inclusive, and a description of the operation of the control circuit is as follows. For the purposes of description, the mechanical details in the circuit shall be given the same reference numerals as similar parts described in connection with Fig. 1.

The circuit generally includes a terminal panel ||2 as a central unit from which lead line wires ||3 and H4, switch control equipment wires ||5 and 0, and the panel has terminals |1 and 8 for wires 5| and 52 that connect with the coil or" the solenoid 2|.

The line wires ||3 and ||4 connect to the bal-- ance of the annealing machine control circuit through a main switch |9 into wires |20 and |2| including a voltmeter |22 to check the potential and indicating lights |23. One side of the line circuit then connects by wire |25 to switch 51 that is normally open and which is closed by plunger or pin 60 when a spring 4 is actuated into position at the annealing station of the machine, at which station spring 4 has its end coils aligned with the electrodes l0 and as diagrammatically indicated in Fig. 6.

Spring 4 thus closes switch 51 to continue the line circuit through wire |26 to the automatic timer |21 which can be set to close the normali open switch |28 for a predetermined interval to suit the timed requirements of the spring feeding mechanism indicated in Fig. 2 or to the requirements of any other synchronized mechanism that controls the interval of advance of each spring to be annealed.

Timer |21 then closes switch |28 so current passes through wire |29 to a quick make and slow break relay |30 which controls the opening and closing of switch |3|. The same circuit includes a slow make and quick break relay |32 that contrcls the opening and closing of switch |33, the circuit being completed through lead |34 back to wire |2|, switch ||9 and to the other side ||4 of the line circuit.

Switches |3| and |33 receive current through wire |35 from the line circuit through wire |20. With switches 51 and |28 closed, coil |30 immediately closes switch |3| creating current flow from wire |35 through leads |36 and 5| to the solenoid 2| from which the circuit is completed through wire |31 to the other side of the line comprising wire ||4. This action causes the operating mechanism of the machine to grip the spring 4 in the manner shown in Fig. 1.

This step is then followed by the closing of switch |33 by the slow make relay |32 sending line current through lead |38 to the coil |39 that causes the closing of the primary contacts |40 and |4| of the primary coil |42 to energize the high potential secondary coil |43. The latter then sends current into the electrodes l and il, and through the spring d to resistance heat the latter.

rlimer l2? will then open the circuit to the relay coils E36 and l32 by opening switch H28. When this occurs switch 33 is immediately opened by the fast break of relay l32 to cut out the transformer circuit and current supply through spring s and this action is immediately followed by opening of switch i3! when the slow break relay E functions. This releases the hold oi the machine on spring fi by de-energization or" the solenoid 2l. Spring d is then moved out and replaced by another at which time the cycle is repeated.

it may be desirable to cut out the automatic control of switch 5l by plunger 66 and to use other switch controlling equipment connected with wires IE5 and H5 through terminals 6M and l d5. In that event switch 5l would be closed by suitable electrical means [L16 connected by suitable leads |41 and M8 to wires H5 and llt.

The circuit controlling operations of the annealing machine are so arranged to allow clear out entry of each spring into the machine to iirst position the spring, to then grip same, and to then supply current ior the annealing cycle. And circuit cuts ori the annealing current prior to release of the spring and also prior to removal of the spring from the electrodes Hi and i l to elirni nate all arcing which is highly objectionable and damaging both tc the product and to the inachine.

Fig. 5 also shows the addition of a coil 'i2 in dotted lines while coil 2l may be used as coil 'il to illustrate the use of this circuit for the Fig. 3 construction of annealing vnachine. Both coils 2i and i2 shown in Fig. 6 can be replaced by pairs of magnetic circuits to control magnetic gripping means such as il and iii) used in Figs. 4 and 5.

Referring to Figs. 7 and 8, this structure contemplates a removable plate lds that carries electrode 55B upon adjacent panel ll. The plate MQ is secured at E52 to the bushings 53 that are molded into the panel iti and the electrode [5E projects through the opening les in the panel ll in a position where it may be contacted by a spring that is to be annealed. In this construction, the electrode stern E55 is threaded to receive the nuts i555 and secure the electrode i523 against the plate ille and to also secure the terminal lill to the electrode. The stem i555 is also provided with a cross opening 53 to permit the insertion ci a rod for rotationally adjusting the electrode "se when a certain portion thereof becomes worn through use.

This particular electrode structure lends itseli to easy replacement of worn electrodes with a minimum amount of time and eort. This structure also has the advantage of being serviced from outside of the spring guiding panels and away from all the mechanism that is housed between the panels for holding the spring in place. Obviously, the entire unit may be replaced by removal or" the bolts 52 or the same process may be followed to remove the units and to merely introduce a new electrode in place of the worn one without changing the plate holding structure. Or an electrode can be reiaced and replaced with a backing shim to again bring the surface of the electrode to its original operative position on a panel.

Having described the mechanisms employed and the control circuits used in carrying out the functions of the mechanisms in annealing springs,

attention should be directed tothe most important advantages that are attained by this invention for annealing springs.

Some or the advantages may be better understood with reference to Figs. 9 to 12 inclusive. Referring to Figs. 9 and 10 wherein each shows the head portion of the same spring in operative contact with its associated electrodes, it should be noticed that the current passes from the electrode in each or" these iigures to the knots it@ and itl at the spring heads and then directly through the coil to the knot on the opposite side. in other words, the current short circuits at the heads of the spring, thus leaving a greater portion oi each head in an unannealed state. In Fig. 9, the portion of the head it?. between the point E63 and the knot itil is left unannealed. In the same spring and in Fig. l0, the portion of the head ltl between the point i555 and the knot le! is also left unannealed.

This particular relationship which is readily obtained by the apparatus of the present invention, has a number of advantages that have to do with the handling and assembling of springs into spring units and so on. When the annealing ma= chine is used in a location to directly receive individual springs from the spring forming machine, these springs are covered with a lubricant from the spring forming machine. This lubricant remains upon the spring head portions iti and i655 in Figs. 9 and lo, while the resu or the spring becomes dry due to the annealing. Obviously, when the springs leave the annealing machine with slick heads such condition is advantageous in separating springs that have been bundled or stacked, and the slick condition oi the spring ends is also extremely advantageous when an operator must assemble the individual springs into composite spring units, r'Ehe slick spring ends greatly aid the operator performing the different spring runt assembly functions by permitting easier threading of the helices or pig-tailed springs through the heads oi the assembled composite spring units. This results in a great saving or time and labor costs.

With a machine of this 1sind, all eXtra handling or" springs from the coiler to the oven and from the oven to an assembly station is eliminated since the springs are heat treated automatically as each leaves the coiler.

This machine provides a dennite channel through which the springs may be passed bodily sidewise which may be adjusted as described in connection with Fig. 3 or by changing the links Si and 3S in Fig. l for accommodating springs of diflerent overall lengths.

Referring to Fig. li, it should be noted that the heads of the springs are normally held parallel by the panels so that the springs come out annealed with each of the heads 8 and il disposed in the parallel planes li and lill. Each spring -ialso leaves its annealing station with the barrel thereof symmetrically disposed about the axial line its and also aligning the heads s and El axially about this line.

Furthermore, the springs are so annealed that the knots it and itil shown in Figs. 9 and lov will always be aligned to facilitate easy stacking and removal o the individual springs from the stacks. Another advantage in annealing springs by this present method is shown in Fig. l2 illustrating the heads ESQ and il@ of an offset type of spring containing the lower onsets lll and lthe upper ofisets Vizi, wherein the annealing process will retain the oisets lll and 172 in the same coplanar relationship with respect to the long axis of the spring. In heat treating springs, the wire used must have certain limits of carbon content to comply with specincations set forth by the steel industry for the manufacture of mattresses or bed springs and the like. The machine of this e invention has the capacity to control the position of the knots or offsets by the time interval of energization, regardless of variations in the carbon content within the range specied by the steel industry. This controlled heat treatment is not possible in spring bundle furnaces.

Where the offset type of spring can be produced with the heads as shown in Fig. 12, any assen.- bled spring structure using springs of this type in connection with the helices or pig-tailed springs will produce a perfectly square and nat assembled spring unit. In all springs that are not of this head aligned form, internal torsion is set up within the spring when assembled into a spring unit to align the heads which results in a distorted assembled spring unit.

Contributing mainly to a perfectly annealed spring having the attributes immediately above set forth is a control circuit which is capable of delivering a current of a given potential through each spring for a given time interval. The method of performing this function, together with the apparatus for holding the spring in the manner described, all tend to produce springs that are uniform and highly desirable for use in all constructions requiring annealed springs. Furthermore, the present method of annealing springs not only produces uniform springs, but does so with considerable saving in cost both as to equipment used and in the cost of the operation of the same. With the machines herein described, power of any volume is only consumed when a spring is actually being annealed which is not the case in the oven method of annealing. An oven must rst be brought up to temperature for use, and much heat is lost each time the oven doors are opened to take out and to replace a bundle or batch of springs.

Although the above description is more specii'ically conned to the various structures illustrated to carry out the automatic annealing of single spring products by the principles set forth under the original concept of this invention, other changes and modifications are also contemplated in these structures without departing from the invention. Such variations in design shall, however, be governed by the breadth and scope of the appended claims directed to the annealing machine of this invention.

What I claim is:

1. A spring annealing machine comprising spaced cooperative guide means to receive a spring therebetween, said guide means acting to direct a spring to a given station, nxed electrodes positioned at said station and in the path of the spring for contact with spaced portions of said spring to send current through said spring to heat the latter at said station, and electrical control equipment connected With said electrodes to energize the latter at predetermined intervals comprising a current supply circuit, a transformer connected with said circuit and with said electrodes, operative means responsive to the positioning of a spring at said station to cause current flow from said transformer to said electrodes and through said spring, and timing means in said circuit to regulate the interval of current ow comprising a circuit control switch to regulate the flow of current to said spring, and timing mechanism to open and close said switch.

2. A spring annealing m chine comprising cooperative guide means to direct a spring along a given path, actuating means to move said spring along said path to a given sta-tion, electrodes positioned at said station to contact portions of said spring to send current through the spring for heat treating the same, mechanism to hold said spring at said station and in contact with said electrodes, a solenoid to actuate the holding mechari m, and electrical control equipment connected with said electrodes to energize the latter at predetermined intervals and to operate said solenoid, said equipment comprising a current supply line circuit connected with said electrodes, a secondary circuit leading from said line circuit to said solenoid, and timing means interposed in said line circuit to control the current ow interval to said electrodes and said solenoid.

3. A spring annealing machine comprising cooperative guide means to direct a spring along a given path, actuating means to move said spring along said path to a given station, electrodes positioned at said station to contact portions of said spring to send current through the spring for heat treating the same, mechanism to hold said spring at said station and in contact with said electrodes, a solenoid to actuate the holding mechanism, and electrical control equipment connected with said electrodes to energize the latter at predetermined intervals and to operate said solenoid, said equipment comprising a current supply line circuit connected with said electrodes, a secondary circuit leading from said line circuit to said solenoid, and timing means interposed in said line circuit to control the current now interval to said electrodes and said solenoid, said timing means including slow make and break relays interposed in said line and secondary circuits to cause the solenoid to function before the electrodes are energized and to continue to function until after the electrodes are de-energized.

4. In a spring annealing machine, guides to direct a spring to a given station, actuating means to move said spring to said station, electrodes at said station to contact opposite ends or" said spring, and operative holding mechanism to engage the opposite ends of said spring and to urge said ends into positive electrical contact against said electrodes, said holding mechanism comprising a toggle, spring gripping ngers at the ends of said toggle, a head connected with the center of said toggle, and a solenoid to actuate said head and toggle.

5. In a spring annealing machine, guides to direct a. spring therebetween to a given stationI actuating means to move said spring along said guides to said station, electrodes at said station to contact opposite ends of said spring, and operative holding mechanism to engage the opposite ends of said spring and to urge said ends into positive electrica-l contact against said electrodes, said holding mechanism comprising movable nngers supported to engage the spring ends, power means connected to actuate said fingers, and resilient means interposed between said power means and said ngers whereby variable thicknesses of spring wire can be accommodated.

6. En a spring annealing machine, guides to direct a spring to a given station, actuating means to move said spring to said station, electrodes at said station to contact opposite ends of said spring, and operative holding mechanism to engage the opposite ends of said spring and to urge said ends into positive electrical contact against said electrodes, said holding mechanism comprising magnets disposed at said station and near said electrodes for gripping said spring ends.

7. In a spring annealing machine, guides to direct a spring to a given station, actuating means to move said spring to said station, electrodes at said station to contact opposite ends of said spring, and operative holding mechanism to engage the opposite ends o said spring and to urge said ends into positive electrical contact against said electrodes, said holding mechanism comprising magnets disposed at said station andnear said electrodes for gripping said spring ends, said holding mechanism comprising pairs of magnets at each electrode to grip the spring ends at such electrodes, each of said pairs of magnets being `positioned along an arc passing through the adjacent electrode with said arc simulating an arc 0i an average sized spring end of a spring to be treated.

8. In a spring annealing machine, insulated guides, a knotted coil spring therebetween with its opposite head coils at said guides respectively, and a pair of electrodes to Contact given peripheral points near the knots of each spring head coil respectively, whereby current may be shunted directly through said coil spring body from knot to knot leaving a greater portion of each head coil unannealed.

9. In a spring annealing machine having insulated panels to receive a spring therebetween, and electrical units arranged to engage end portions of said spring, said units comprising a nxture, an electrode releasably secured to said xture, said panel having an opening, and means to secure said xture to said panel with said electrode extending through said panel opening and disposed for contact by a spring.

10. In a spring annealing machine having insulated panels to receive a spring therebetween, and electrical units arranged to engage end portions of said spring, said units comprising a fixture, an electrode releasably secured to said fixture, said panel having an opening, and means to secure said fixture to said panel with said electrode extending through said panel opening and disposed for contact by a spring, and said electrode having rotatable means to bodily revolve said electrode to present another portion of said electrode for contact by a spring.

11. The method of annealing individual knotted. coil springs consisting of the step of prepositioning each coil spring in a given head to head space, retaining each coil in this position with the head coil knots aligned, passing a current through said spring between portions of said head coils, and supplying said current at a given potential and for a given interval of time.

12.1n a spring annealing machine, spaced n guide members to receive a spring end to end therebetween, trackways associated with said guide members for circumferential contact with peripheral portions of a spring to direct the latter along a given path between said guide members, and electrical contact units positioned along the path of movement of the spring to shunt an electrical current therethrough, and operable feed means to abut and to bodily actuate a spring along said trackways and along said given path h between said guide members,

13. In a spring annealing machine, spaced guide members to receive a spring end to end therebetween, trackways associated with said guide members for circumferential Contact with peripheral portions of a spring to direct the latter along a given path between said guide members, and heat transmitting means arranged along the path of `movement of the spring to supply heat thereto, and operable feed means to directly engage an integral portion of a spring and to bodily actuate said spring along said trackways and between said guide members.

14. In a spring annealing machine, spaced guide members to receive a spring end to end therebetween, trackways associated with said guide members for circumferential contact with peripheral portions of a spring to direct the latter along a given path between said guide members, and electrical Contact units positioned along the path of movement of the spring to shunt an electrical current therethrough, and rockable lingers to engage the trackway contacting portions of a spring to hold the latter adjacent said;

electrical contact units.

15. In a spring annealing machine, spaced guide members to receive a spring end to end therebetween, trackways associated with said guide members for circumferential contact with peripheral portions of a spring to direct the latter along a given path between said guide members, and heat transmitting means arranged along the path of movement of the spring to supply heat thereto, and rockable lingers to engage the trackway contacting portions of a spring to hold the latter adjacent said heat transmitting means.

16. In a spring annealing machine, spaced guide members to receive a spring end to end therebetween, trackways associated with said guide members for circumferential contact with peripheral portions of a spring to direct the latter along a given path between said guide members, and electrical contact units positioned along the path of movement of the spring to shunt an electrical current therethrough, and rockable fingers to engage the trackway contacting portions of a spring to hold the latter adjacent said electrical contact units, said fingers having their spring contacting portions movable over and adjacent said trackways with the terminal ends directed toward said spaced guide members.

17. In a spring annealing machine, spaced guide members to receive a spring end to end therebetween, trackways associated with said guide members for circumferential contact with peripheral portions of a spring to direct the latter along a given path between said guide members, and electrical Contact units positioned along the path of movement of the spring to shunt an electrical current therethrough, and rockable iingers to engage the trackway contacting portions of 4a spring to hold the latter adjacent said electrical contact units, said ngers having their spring contacting portions movable over and adjacent said trackways with the terminal ends directed toward said spaced guide members, and said terminal ends of said nngers being inclined to urge the contacted portions of the spring ends toward said guide members and simultaneously against said trackways.

18. A spring annealing machine comprising spaced guide members to receive a spring therebetween, spring supporting members to position said spring in a given location with respect to said spaced guide members, electrodes connected with certain of said members for Contact with opposite ends of said spring when the latter is disposed in said given location with respect to said members, and clamping units carried by certain 0f Said members and arranged to individ- 13n ually urge the spring ends respectively against said certain members and to hold said spring ends in xefl relation against said electrodes.

19. A spring annealing machine comprising spaced panels, bodily shiftable feed fingers for engaging a spring to actuate said spri Lg in sidewise relation between and relative to said panels, guide means interposed between said panels arranged for contact by said spring and to di rect the spring to a given station between said panels, and electrical contact units to engage the ends of said spring at said station.

20. A spring annealing machine comp sing spaced cooperative guide means to receive a spring transversely therebetween with the end portions of the spring `disposed adjacent said cooperative guide means, spring supporting bars independently mounted on each of g means respectively for edge Contact with transversely spaced portions of said spring, actuating means to direct said spring bodily over said supporting bars and between said guide means toward a given station, and electrodes positioned at said station for contact with spaced portions of said spring to send current through the spring and to heat the latter between said spaced portions thereof.

21. A spring annealing machine comprising spaced cooperative guide means to receive a spring transversely therebetween with the end portions of the spring disposed adjacent said cooperative guide means, support bars independ ently mounted on each of said guide means respectively to provide a guiding trackway for edge Contact with transversely spaced portions of said spring and to direct said spring bodily toward a given station, and electrodes positioned at said station for contact with spaced portions of said spring to send current through the spring and to heat the latter between said spaced portions thereof, and current control means connected with said electrodes and including operative means responsive to said spring when in said station position to energize said electrodes.

22. A spring annealing machine comprising spaced cooperative spring end guides to receive a spring transversely therebetween, rail means associated with said spring end guides to support said spring at peripheral portions thereof for rolling motion between said spring end guides and acting to direct a spring to a given station, operative means to actuate a spring over said rail means and between said guides to said station, electrodes positioned at said station for contact with spaced portions of said spring to send current through said spring to heat the latter, and electrical control equipment connected with said electrodes to energize the latter at predetermined intervals.

23. A spring annealing machine comprising spaced cooperative guide means to receive a spring transversely therebetween, rails Xedly connected with said guide means respectively to support the spring ends peripherally and acting to direct a spring to a given station, fixed elec-- trodes positioned in the rail guided path of the spring at said station for contact with spaced portions of said spring to send current through spring at said station to heat the spring, and electrical control equipment connected with said electrodes to energize the latter at predetermined intervals, said electrical control equipment including current iiow timing means to regulate the current heating interval of the spring.

24. A spring annealing machine comprising spaced cooperative guide means for contact with the laterally outward faces of the head ends oi a spring, transversely spaced supporting means arranged between said guide means for engagement with the peripheral edge portions of said head ends of the spring respectively and comrising means to guide a spring along a given path to a given station between said guide means, electrodes positioned at said station for contact with spaced portions of said spring to send current through said spring to heat the latter, and electrical control equipment connected with said electrodes to energize the latter at predetermined intervals, said electrical control equipment in cluding transformer mechanism having a predetermined energy output and connected with said electrodes to pass a current of given potential through said spring.

25. A spring annealing machine comprising spaced cooperative guide means to receive a spring therebetween and to engage the end portions of said spring, said guide means acting to direct a spring by its end portions to a given station, electrodes positioned at said station for contact with spaced portions of said spring to send current through said spring at said station to heat the spring, and an electrical circuit, control equipment in said circuit connected with said electrodes to energize the latter at predetermined intervals, said control equipment including transformer mechanism having a predetermined energy output in circuit with said electrodes to pass a current of given potential through said spring, and timing means interposed in said electrode circuit to regulate the interval of current iiow through said spring comprising a circuit control switch to regulate the flow of current to said spring, and timing mechanism to open and close said switch.

2G. In a spring annealing machine, spring guides to direct a spring to a given s'tation, actuating means to engage and bodily move said spring along said guides and to said station, electrodes at said station and in Contact with the opn posite ends of a spring there located, and spring holding units operative to engage the opposite ends of said spring respectively and to urge said ends individually into positive electrical contact against each of said electrodes respectively.

27. The method of annealing individual coil springs having knotted head ends thereon which consists of the step of locating a spring with the head ends thereof subject to opposite polarity electrical current sources, introducing an electrical current through said spring and from one head end knot thereon to the other head end knot thereon, and maintaining said knot to knot current active at a given potential and for a given interval of time.

28. In a spring annealing machine, longitudinally arranged spaced guide members to transversely receive a spring end to end therebetween, individual trackways longitudinally positioned in a fixed relation with respect to said guide members and arranged in laterally spaced relation bew tween said guide members for individual circumferential contact with the peripheries of the end portions of a spring, said trackways providing guide means for said spring end portions and being arranged along a given path between said guide members, and electrical contact units positioned along the path of movement of the spring to shunt an electrical current therethrough.

29. In a spring annealing machine, laterally spaced guide members to receive a spring end to end therebetween, individual trackways for each of said guide members and positioned in laterally spaced relation between said guide members and extending in the general direction of the latter to provide circumferential edge contact for the spring ends respectively whereby to direct said spring along a given path between said guide members, and heat transmitting` means arranged along the guided path of movement of the spring to supply heat thereto.

30. A spring annealing machine having a spring handling guideway and means to move said spring therealong, said guideway comprising spaced wall members to guide endwise spaced portions of a transversely positioned spring between said wall members, iiXed guide units on said wall members to support circumferential edge portions of said spring in a given relation with respect to said wall members and to guide said spring to a given station between said Wall members, and electrodes on said wall members for contacting engagement with spaced segments of said spring to introduce electrical energy into said spring and between said spaced segments of said spring.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,105,105 Zimmerman Jan. 1l, 1938 2,116,327 Simmons M ay 3, 1938 2,124,329 Zimmerman Julf,T 19, 1938 2,254,525 Hathaway et a1. Sept. 2, 1941 

